A cross-sectional study of the microorganisms found in periodontal pockets of 40 patients suffering from AIDS will be performed to determine the (1) identity and (2) numbers of those Gram negative and Gram positive bacteria which most commonly inhabit these sites. The survey will be conducted in a manner such that it will be as unbiased as possible and will reveal the presence and numbers of anaerobic bacteria, aerobic bacteria, spirochetes and certain fungi. The contractor shall analyze plaque samples from one healthy site and one diseased periodontal site for cultivable flora from each of 40 AIDS patients recruited from a preexisting program within NIH. Sampling and cultivation shall be performed using protocols and media that maximize the capture of the extant flora in as unbiased a fashion as possible.